textproduct: Quad Cities

KEY MESSAGES

- An active weather pattern will continue tonight through Monday, with potential for strong to severe storms each day. Confidence on areal coverage and timing remains low.

- After warm and more humid conditions into early next week, a strong cold front will sweep through the area Tuesday, bringing cooler conditions by mid-week next week.

SHORT TERM /THROUGH SUNDAY NIGHT/

Issued at 246 PM CDT Sat May 16 2026

Early this afternoon, we are seeing a general lull in showers and thunderstorms during the ongoing active weather pattern. There is an area of decaying showers and isolated storms across our far south near an area of higher 700 mb level moisture. This activity doesn't appear to pose a strong to severe storm threat, and has largely diminished by this writing. Elsewhere, we're keeping a close eye on an approaching mid-level shortwave impulse from the central Plains region, which can be seen on the GOES-East mid-level water vapor imagery. Additionally, a warm frontal zone continues to be draped over our region along the Interstate 80 corridor, extending from a surface low over the central Plains. This front/shortwave combination should help provide the support for increasing chances of showers/storms late this afternoon through tonight. Confidence for areal coverage remains low, given the amount of spread among the CAM guidance. However, they all agree on some showers and storms developing later this afternoon/evening, initiating as isolated cells, becoming more widespread with time. SBCAPE values per the 16.12z HREF ensemble are progged around 1000-2000 J/kg along and south of the warm front. Mid-level lapse rates and deep-layer shear appears to be more marginal, given pretty weak 850 to 500 mb flow overhead. Still, as storms begin to cluster together, they should result in more of a localized damaging wind threat, along with isolated large hail. SPC has expanded the Slight Risk (level 2 of 5) for severe storms over eastern Iowa, northeastern Missouri, and portions of east-central Illinois.

As we go through the overnight hours into Sunday morning, strong to severe storm potential appears to wane (especially after 2 AM tonight), but heavier showers and isolated storms remain possible. The Plains region surface low appears to elongate to the northeast for Sunday and upper-level flow becomes more southerly, which should help lift any showers/storms over central Iowa northeastward Sunday morning. Late Sunday morning and afternoon will be quite gusty over the area, as boundary layer mixing commences due to daytime heating. Mixing heights aren't expected to be too deep, but strong flow over the low-levels of the atmospheric profile should support enhanced momentum transport and gusts between 25 to 35 mph are expected. During this time, a dry sounding profile can be seen among the various guidance and HREF/REFS ensembles, including an EML aloft to help limit convective development. This would suggest that if any convection develops Sunday afternoon, it would be more isolated in nature. It's possible (even perhaps likely) conditions will stay dry Sunday afternoon and evening.

As we go into Sunday night, the main focus will be on an incoming line of showers and storms late Sunday night into early Monday morning, which appears to be the decaying remnants of a complex of severe storms that's progged to develop over the Missouri River valley. Other than any lingering storms on Sunday morning, this appears to be our other potential for storms during the Day 2 period (7 AM Sunday - 7 AM Monday). This signal suggests a more limited severe weather potential than before, and hence, SPC has largely reduced the Slight Risk coverage for Day 2 for us (other than a portion of our far northwest remaining in the Slight Risk). A Marginal Risk (level 1 of 5) does remain over most of our CWA, mainly along and west of a line from Rockford, IL to Carthage, IL. Locally strong wind gusts and large hail appear to the main threats will any strong to severe storms that form Sunday.

LONG TERM /MONDAY THROUGH SATURDAY/

Issued at 246 PM CDT Sat May 16 2026

A stronger cold front will look to organize upstream acrs the plains and Upper MO RVR Valley on Monday. We may still be dealing with morning convection or lingering MCS from late Sunday night, and this will impact what happens for the rest of the day. The stronger storm regeneration may focus out along that feature Monday and Monday night, with lingering remnants sweeping this way with the front by Tuesday morning. Uncertainty is still there with regards to any severe threat Tuesday, which is largely dependent upon the frontal timing and may be a larger risk just off to the southeast of the local area. Then, post-frontal cooler and more seasonable conditions look to settle in mid next week.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/

Issued at 540 PM CDT Sat May 16 2026

Considerable uncertainty still persists about when and where showers and thunderstorms will occur this evening into tonight. CAMs still show a variety of solutions of how precipitation evolves over the next several hours. Thus, have mostly continued TEMPOs and PROB30s from previous TAF issuance. Did remove PROB30 for -TSRA at MLI this evening as -TSRA should arrive a few hours later (during the 05-09z TEMPO). MLI and BRL will remain VFR outside of precip while CID and DBQ will flirt with MVFR cigs for a few hours Sunday morning. This is especially true for DBQ. Southeasterly winds of 5-10 knots tonight increase during Sunday morning and turn southerly. Winds will range from 15-18 knots sustained with gusts to near 30 knots Sunday afternoon.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.